Re: xfstests 073 regression

Wu Fengguang
2011-08-02T11:44:38Z

On Tue, Aug 02, 2011 at 12:52:42AM +0800, Christoph Hellwig wrote:
> wb_check_background_flush is indeed what we're hitting.

That means s_umount is NOT held by another queued writeback work.

> See the trace output using a patch inspired by Curt's below:
>
> # tracer: nop
> #
> # TASK-PID CPU# TIMESTAMP FUNCTION
> # | | | | |
> <...>-4279 [000] 113.034052: writeback_grab_super_failed: bdi 7:0: sb_dev 0:0 nr_pages=9223372036854775807 sync_mode=0 kupdate=0 range_cyclic=1 background=1 reason=wb_check_background_flush
> <...>-4279 [000] 113.034052: writeback_grab_super_failed: bdi 7:0: sb_dev 0:0 nr_pages=9223372036854775807 sync_mode=0 kupdate=0 range_cyclic=1 background=1 reason=wb_check_background_flush
> <...>-4279 [000] 113.034052: writeback_grab_super_failed: bdi 7:0: sb_dev 0:0 nr_pages=9223372036854775807 sync_mode=0 kupdate=0 range_cyclic=1 background=1 reason=wb_check_background_flush

What's that bdi 7:0? And sb_dev=0:0, nr_pages=9223372036854775807=0x7fffffffffffffff.

All are indicating some special bdi/inode.

Thanks,
Fengguang